Oh you have a few more to go. Long time ago when Nilbog punnished like 300 + accounts he knocked down level 60 people to level 54 1/2. I think at that level you need 60% more XP to make it back to 60. Here is a link to Wiki. Down towards the bottom. Read and weep.
http://wiki.project1999.org/Game_Mec...ement_by_Level